[MM-53968] Includes mattermost-plugin-api into the mono repo (#24235)

Include https://github.com/mattermost/mattermost-plugin-api into the mono repo

Co-authored-by: Jesse Hallam <jesse.hallam@gmail.com>
Co-authored-by: Michael Kochell <mjkochell@gmail.com>
Co-authored-by: Alejandro García Montoro <alejandro.garciamontoro@gmail.com>
Co-authored-by: Ben Schumacher <ben.schumacher@mattermost.com>
Co-authored-by: Alex Dovenmuehle <alex.dovenmuehle@mattermost.com>
Co-authored-by: Michael Kochell <6913320+mickmister@users.noreply.github.com>
Co-authored-by: Christopher Poile <cpoile@gmail.com>
Co-authored-by: İlker Göktuğ Öztürk <ilkergoktugozturk@gmail.com>
Co-authored-by: Shota Gvinepadze <wineson@gmail.com>
Co-authored-by: Ali Farooq <ali.farooq0@pm.me>
Co-authored-by: Maria A Nunez <maria.nunez@mattermost.com>
Co-authored-by: Daniel Espino García <larkox@gmail.com>
Co-authored-by: Christopher Speller <crspeller@gmail.com>
Co-authored-by: Alex Dovenmuehle <adovenmuehle@gmail.com>
Co-authored-by: Szymon Gibała <szymongib@gmail.com>
Co-authored-by: Lev <1187448+levb@users.noreply.github.com>
Co-authored-by: Jason Frerich <jason.frerich@mattermost.com>
Co-authored-by: Agniva De Sarker <agnivade@yahoo.co.in>
Co-authored-by: Artur M. Wolff <artur.m.wolff@gmail.com>
Co-authored-by: Madhav Hugar <16546715+madhavhugar@users.noreply.github.com>
Co-authored-by: Joe <security.joe@pm.me>
Co-authored-by: Ibrahim Serdar Acikgoz <serdaracikgoz86@gmail.com>
Co-authored-by: José Peso <trilopin@users.noreply.github.com>

server/public/pluginapi/store.go

@@ -0,0 +1,117 @@
+package pluginapi
+
+import (
+	"database/sql"
+	"sync"
+
+	// import sql drivers
+	_ "github.com/go-sql-driver/mysql"
+	_ "github.com/lib/pq"
+
+	"github.com/mattermost/mattermost/server/public/plugin"
+	"github.com/mattermost/mattermost/server/public/shared/driver"
+	"github.com/pkg/errors"
+)
+
+// StoreService exposes the underlying database.
+type StoreService struct {
+	initialized bool
+	api         plugin.API
+	driver      plugin.Driver
+	mutex       sync.Mutex
+
+	masterDB  *sql.DB
+	replicaDB *sql.DB
+}
+
+// GetMasterDB gets the master database handle.
+//
+// Minimum server version: 5.16
+func (s *StoreService) GetMasterDB() (*sql.DB, error) {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+
+	if err := s.initialize(); err != nil {
+		return nil, err
+	}
+
+	return s.masterDB, nil
+}
+
+// GetReplicaDB gets the replica database handle.
+// Returns masterDB if a replica is not configured.
+//
+// Minimum server version: 5.16
+func (s *StoreService) GetReplicaDB() (*sql.DB, error) {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+
+	if err := s.initialize(); err != nil {
+		return nil, err
+	}
+
+	if s.replicaDB != nil {
+		return s.replicaDB, nil
+	}
+
+	return s.masterDB, nil
+}
+
+// Close closes any open resources. This method is idempotent.
+func (s *StoreService) Close() error {
+	s.mutex.Lock()
+	defer s.mutex.Unlock()
+
+	if !s.initialized {
+		return nil
+	}
+
+	if err := s.masterDB.Close(); err != nil {
+		return err
+	}
+
+	if s.replicaDB != nil {
+		if err := s.replicaDB.Close(); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// DriverName returns the driver name for the datasource.
+func (s *StoreService) DriverName() string {
+	return *s.api.GetConfig().SqlSettings.DriverName
+}
+
+func (s *StoreService) initialize() error {
+	if s.initialized {
+		return nil
+	}
+
+	if s.driver == nil {
+		return errors.New("no db driver was provided")
+	}
+
+	config := s.api.GetUnsanitizedConfig()
+
+	// Set up master db
+	db := sql.OpenDB(driver.NewConnector(s.driver, true))
+	if err := db.Ping(); err != nil {
+		return errors.Wrap(err, "failed to connect to master db")
+	}
+	s.masterDB = db
+
+	// Set up replica db
+	if len(config.SqlSettings.DataSourceReplicas) > 0 {
+		db := sql.OpenDB(driver.NewConnector(s.driver, false))
+		if err := db.Ping(); err != nil {
+			return errors.Wrap(err, "failed to connect to replica db")
+		}
+		s.replicaDB = db
+	}
+
+	s.initialized = true
+
+	return nil
+}